actions/release-monthly/action.yml

---
# yaml-language-server: $schema=https://json.schemastore.org/github-action.json
name: Do Monthly Release
description: 'Creates a release for the current month, incrementing patch number if necessary.'
author: 'Ismo Vuorinen'

branding:
  icon: calendar
  color: blue

inputs:
  token:
    description: 'GitHub token with permission to create releases.'
    required: true
    default: '${{ github.token }}'
  dry-run:
    description: 'Run in dry-run mode without creating the release.'
    required: false
    default: 'false'
  prefix:
    description: 'Optional prefix for release tags.'
    required: false
    default: ''

outputs:
  release-tag:
    description: 'The tag of the created release'
    value: ${{ steps.create-release.outputs.release_tag }}
  release-url:
    description: 'The URL of the created release'
    value: ${{ steps.create-release.outputs.release_url }}
  previous-tag:
    description: 'The previous release tag'
    value: ${{ steps.create-release.outputs.previous_tag }}

runs:
  using: 'composite'
  steps:
    - name: Validate Inputs
      shell: bash
      run: |
        set -euo pipefail

        # Validate token
        if [ -z "${{ inputs.token }}" ]; then
          echo "::error::GitHub token is required"
          exit 1
        fi

        # Validate dry-run option
        if [ "${{ inputs.dry-run }}" != "true" ] && [ "${{ inputs.dry-run }}" != "false" ]; then
          echo "::error::dry-run must be either 'true' or 'false'"
          exit 1
        fi

        # Validate prefix format if provided
        if [ -n "${{ inputs.prefix }}" ]; then
          if ! [[ "${{ inputs.prefix }}" =~ ^[a-zA-Z0-9_.-]*$ ]]; then
            echo "::error::Invalid prefix format. Only alphanumeric characters, dots, underscores, and hyphens are allowed"
            exit 1
          fi
        fi

    - name: Checkout Repository
      uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
      with:
        fetch-depth: 0 # Fetch all history for tag comparison

    - name: Create Release
      id: create-release
      shell: bash
      env:
        GITHUB_TOKEN: '${{ inputs.token }}'
      run: |
        set -euo pipefail

        # Function to validate version format
        validate_version() {
          local version=$1
          if ! [[ $version =~ ^[0-9]{4}\.[0-9]{1,2}\.[0-9]+$ ]]; then
            echo "::error::Invalid version format: $version"
            return 1
          fi
        }

        # Function to get previous release tag with error handling
        get_previous_tag() {
          local previous_tag
          previous_tag=$(gh release list --limit 1 2>/dev/null | awk '{ print $1 }') || {
            echo "::warning::No previous releases found"
            return 1
          }
          echo "$previous_tag"
        }

        # Get previous release tag
        previous_tag=$(get_previous_tag) || previous_tag=""
        echo "previous_tag=${previous_tag}" >> $GITHUB_OUTPUT

        if [ -n "$previous_tag" ]; then
          previous_major="${previous_tag%%\.*}"
          previous_minor="${previous_tag#*.}"
          previous_minor="${previous_minor%.*}"
          previous_patch="${previous_tag##*.}"

          # Validate previous tag format
          validate_version "$previous_tag" || {
            echo "::error::Invalid previous tag format: $previous_tag"
            exit 1
          }
        fi

        # Determine next release tag
        next_major_minor="$(date +'%Y').$(date +'%-m')"

        if [ -n "$previous_tag" ] && [[ "${previous_major}.${previous_minor}" == "${next_major_minor}" ]]; then
          echo "Month release already exists for year, incrementing patch number by 1"
          next_patch="$((previous_patch + 1))"
        else
          echo "Month release does not exist for year, setting patch number to 0"
          next_patch="0"
        fi

        # Construct release tag
        release_tag="${next_major_minor}.${next_patch}"
        if [ -n "${{ inputs.prefix }}" ]; then
          release_tag="${{ inputs.prefix }}${release_tag}"
        fi

        # Validate final release tag
        validate_version "${release_tag#${{ inputs.prefix }}}" || {
          echo "::error::Invalid release tag format: $release_tag"
          exit 1
        }

        echo "release_tag=${release_tag}" >> $GITHUB_OUTPUT

        # Create release if not in dry-run mode
        if [ "${{ inputs.dry-run }}" = "false" ]; then
          echo "Creating release ${release_tag}..."
          release_url=$(gh release create "${release_tag}" \
              --repo="${GITHUB_REPOSITORY}" \
              --title="${release_tag}" \
              --generate-notes 2>/dev/null) || {
            echo "::error::Failed to create release"
            exit 1
          }
          echo "release_url=${release_url}" >> $GITHUB_OUTPUT
          echo "Release created successfully: ${release_url}"
        else
          echo "Dry run mode - would create release: ${release_tag}"
          echo "release_url=dry-run" >> $GITHUB_OUTPUT
        fi

    - name: Verify Release
      if: inputs.dry-run == 'false'
      shell: bash
      env:
        GITHUB_TOKEN: '${{ inputs.token }}'
      run: |
        set -euo pipefail

        # Verify the release was created
        if ! gh release view "${{ steps.create-release.outputs.release_tag }}" &>/dev/null; then
          echo "::error::Failed to verify release creation"
          exit 1
        fi

        echo "Release verification successful"